Precise and efficient navigation systems are very important for many applications involving location identification, route planning, autonomous robot navigation, unknown environment map building, etc. However, most of the available navigation systems do not function efficiently and fail frequently under certain circumstances.
For example, GPS (Global Positioning System) is a widely used navigation system. However, GPS is limited in that it cannot work reliably once the satellite signals are blocked or unavailable in, for example, “GPS-denied” environments such as indoors, forests, urban areas, etc. Even when operating properly, GPS can only provide the location of the user, which is not sufficient to assist the user during navigation. For example, when a group of military personnel are performing a military operation in an unknown environment, it is desirable to determine not only the location of each member of the unit, but also identify what each user in the group is seeing, where they are looking (i.e., whether they are viewing a region or target of interest, and the movement and/or direction of the user's visual perspective), and any other activity and happenings in the scene. In addition, it is highly desirable to have a system wherein the individual members of the team are able to share visual and navigational information with one another.
In addition, conventional systems including multiple cameras or other visual sensing devices provide for limited ability to perform comprehensive visual odometry. Specifically, in such systems, visual odometry can be applied to each camera individually to estimate the pose of that camera. As such, the relative poses of the cameras (i.e., a camera's pose relative to the other cameras in the system) are fixed and known, which constrains the single-camera results. In this regard, conventional navigation systems provide for the generation of camera pose hypotheses that are based exclusively on data which is specific to the individual camera, and does not take into account the data processed by the other camera's in the multi-camera system.
Therefore, there is a need for a method and a system for efficiently and effectively determine navigational information using a multi-camera system.